Deflake TaskDispatchThreadTest.MultipleDelayedTasksOrder - #57830
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Summary: WARNING: Generated by Autopilot (alpha) — review carefully, verify the underlying claim before accepting. Agent: React Native Oncall Tests Fixer | Trajectory: https://www.internalfb.com/intern/devai/devmate/inspector/0bb8944e-85d4-4a86-ac19-5147b3b0a48f/ | SC job: https://www.internalfb.com/intern/sandcastle/instance/36028799852645402/ --- `TaskDispatchThreadTest/MultipleDelayedTasksOrder` (test_id 562950261618811) is a timing-sensitive GTest that schedules two delayed tasks (at 50ms and 100ms) and then races a fixed `std::this_thread::sleep_for(120ms)` against the 100ms deadline before asserting `results.size() == 2`. Only 20ms of slack covers the later task, so under CI load / emulator scheduling jitter the second task has not run when the assertion fires, producing the observed `results.size()` is 0 or 1 failure at line 79. TestX reports a 95.7% simple flakiness score for this test, and it has a long history of auto-closed FLAKY issues; it recently surfaced as a hard FAILURE (issue 233255291). Replace the fixed sleep with deterministic synchronization on the later task using the same `std::promise`/`future.wait_for` pattern already used by `RunAsyncWithDelay` in this file. Because both tasks run serially on the single dispatch thread in deadline order, blocking until the 100ms task completes guarantees the 50ms task has already run, and waiting on the future establishes the happens-before needed to read `results` safely. Differential Revision: D114605936
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Summary:
WARNING: Generated by Autopilot (alpha) — review carefully, verify the underlying claim before accepting.
Agent: React Native Oncall Tests Fixer | Trajectory: https://www.internalfb.com/intern/devai/devmate/inspector/0bb8944e-85d4-4a86-ac19-5147b3b0a48f/ | SC job: https://www.internalfb.com/intern/sandcastle/instance/36028799852645402/
TaskDispatchThreadTest/MultipleDelayedTasksOrder(test_id 562950261618811)is a timing-sensitive GTest that schedules two delayed tasks (at 50ms and
100ms) and then races a fixed
std::this_thread::sleep_for(120ms)againstthe 100ms deadline before asserting
results.size() == 2. Only 20ms of slackcovers the later task, so under CI load / emulator scheduling jitter the
second task has not run when the assertion fires, producing the observed
results.size()is 0 or 1 failure at line 79. TestX reports a 95.7% simpleflakiness score for this test, and it has a long history of auto-closed
FLAKY issues; it recently surfaced as a hard FAILURE (issue 233255291).
Replace the fixed sleep with deterministic synchronization on the later
task using the same
std::promise/future.wait_forpattern already used byRunAsyncWithDelayin this file. Because both tasks run serially on thesingle dispatch thread in deadline order, blocking until the 100ms task
completes guarantees the 50ms task has already run, and waiting on the future
establishes the happens-before needed to read
resultssafely.Differential Revision: D114605936